Al Gore knows a thing or two about the vicissitudes of public life. Six years ago he was virtually written off as a has-been vice-president after he won the popular vote only to lose the 2000 race for the White House. On Sunday night his rehabilitation was completed as he was crowned the moral mouthpiece of Hollywood, receiving an Oscar for his global warming documentary An Inconvenient Truth.

In front of the cream of the movie industry and the world's cameras, he stood alongside fellow eco-warrior Leonardo DiCaprio and proclaimed the ceremony the first in the Academy Awards' history to be run on "environmentally intelligent" lines. "And you know what?" he told the adoring crowd. "It's not as hard as you might think. We have a long way to go but all of us can do something in our own lives to make a difference."

Twenty four hours is a long time in green politics. By Monday night Mr Gore found himself back in that all-too familiar place - the eye of the storm.

A little-known group based in his home state, the Tennessee Centre for Policy Research, had the idea of looking up Mr Gore's energy bills for his large home in the Belle Meade area of Nashville to see whether he practised what he preached.

The headline figures, released to the group under federal freedom of information rules, were striking. Last year the Gore household consumed 221,000 kilowatt-hours (kWh) of electricity - more than 20 times the national annual average.

His household consumption of energy rose between 2005 and 2006, the bills showed, from 16,200 kWh a month to 18,400 kWh last year. In addition, he spent on average $1,080 (£550) a month on natural gas. Combined, his electricity and gas bills reached almost $30,000.

The group released the information on Monday night under the title "Al Gore's personal energy use is his own inconvenient truth". Its president, Drew Johnson, told the Guardian that he had no objection to someone spending $30,000 on energy to light and heat a multimillion dollar house. "I only have a problem with that person telling us what light-bulbs to buy and that we should get a new low-energy refrigerator. That's hypocrisy, and I'm proud to have exposed it," he said.

By yesterday the news of Mr Gore's energy bills was flying around the internet at a rate which, were the web petrol-powered, would have led to instant sea level rises. Conservative and libertarian bloggers, from Instapundit to Hot Air and Red State, luxuriated over the details, while progressive and liberal blogs led by the Huffington Post tried to discredit the report by describing it as a typical smear campaign. It had been timed for the Oscars, the Post's blogger said, by a group that had no official status and had connections with rightwing groups funded by ExxonMobil.

Mr Johnson denied the oil industry link and said he had no intention of smearing Mr Gore, but had been motivated simply by a desire to hold public figures to account.

His group, which is registered as a non-profit organisation, describes itself as an independent thinktank that promotes a vision of a free society grounded in property rights, individual liberty and limited government.

By yesterday morning Mr Gore's team was pulled into the controversy. Kalee Kreider, his environmental adviser, told the Guardian that "you can attack the messenger but the message remains the same". She said Mr Gore's fuel bills failed to tell the whole picture. All the energy used for the Nashville home came from a green power provider to the Tennessee Valley that draws its energy from solar, wind-powered and methane gas supplies, among other sources.

The Gores were installing solar panels on the roof of their home, Ms Kreider added, and making efforts to reduce their energy needs. Besides, Mr Gore had adopted a "carbon neutral" life whereby any emissions for which he was personally responsible were offset by buying green credits such as parcels of forests.

"The point about vice-president Gore is that he's devoted 30 years of his life to educating people about global warming. That says something about the man," she said.

Laurie David, the producer of An Inconvenient Truth, said that the furore was only to be expected. A leading global warming campaigner, she is familiar with criticism of this kind having been called a "jetstream liberal" for using private planes. "What this lame attempt to discredit Al Gore tells me is that we are winning. This is comedy at its best - it's straight out of the David Letterman show."

Mr Gore, or the Goracle as he is now known, has so far kept out of the fray. He is flying high, his old image as Bill Clinton's wooden sidekick long since forgotten. The Washington Post has dubbed him Al Gore: rock star, and he is planning a global round of Live Earth concerts for the summer. Rumours persist that he will make a late run for the 2008 election, prompting an elaborate joke at the Oscars in which he pretended to be announcing a presidential bid only to be shooed off stage.

With all that riding in his favour, he will wish to swat away the present noise as quickly as possible. If nothing else, though, this is a reminder that in politics - even if it's green - you should never take anything for granted.